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Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Papua Jalan Gunung Salju Amban, Manokwari 98314
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Jurnal Natural
Published by Universitas Papua
ISSN : 14121328     EISSN : 2746427X     DOI : -
Core Subject : Science, Education, Agriculture,
Agriculture, Biological Sciences & Forestry Chemistry Mathematics Physics
Jurnal Natural merupakan jurnal ilmu-ilmu matematika dan pengetahuan alam (basic science) untuk bidang: matematika, kimia, statistika, biologi, dan fisika termasuk ilmu terapan yang terkait seperti bioteknologi, kimia pangan, keanekaragaman hayati, dan lain-lain.
Arjuna Subject : Umum - Umum
Articles 160 Documents
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DAMPAK KEKERINGAN TERHADAP KESTABILAN SISTEM MANGSA PEMANGSA DENGAN FUNGSI RESPON HOLLING TIPE III DAN HASIL PEMANENAN KONSTAN PADA MANGSA Muhlis, La Ode; Rium Hilum, Rium Hilum; Mahmud, Mahmud
Jurnal Natural Vol. 19 No. 2 (2023): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v19i2.251

Abstract

ABSTRACT: The dynamic relationship between prey populations and predator populations can be represent in the mathematical model. This research was developed from the mathematical model of predator-prey which was first introduced by Lotka-Volterra, namely by increasing the realism of the model through apply the logistic model to the prey and involving Holling type-III response function. The effects of drought on both populations and constant harvesting of prey are also included in the mathematical model. After the mathematical model is formed, a nondimensional model is then carried out to create a shape from the model that was built previously. This study aims to analyze the impact of drought on the prey-prey system with a type III Holling functional response and constant-yield prey harvesting. There is at least one equilibrium point and there are at most three equilibrium points in the model. Numerical simulations are carried out on the model to see the phase portrait. The simulation results show that if the rate of drought is greater than the intrinsic growth rate of prey then both populations will go towards extinction. However, on the other hand, if the intrinsic growth rate of the prey is greater than the rate of drought, then the dynamics relationship between the predator and prey populations depends on the pattern of constant-yield prey harvesting. Thus, a stable dynamic relationship occurs on the constant-yield prey harvesting at the interval 0<h<=K(r-a1)2
Kualitas Air Sumur Dekat SPBU Rendani Kelurahan Wosi Kecamatan Manokwari Barat Kabupaten Manokwari Provinsi Papua Barat Mamengko, David Victor; Raharjo, Syafrudin; Kusumo, Pribowo Angling; Lestari, Agnes Dyah Novitasari
Jurnal Natural Vol. 19 No. 2 (2023): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v19i2.256

Abstract

Wells are a groundwater source that is widely used by Indonesian citizens for sanitation and hygiene purposes. Well water quality is influenced by internal factors, namely the condition of the well itself, and external factors, namely the environment around the well. This research aims to analyze the quality of well water near the Rendani gas station, Wosi Village, West Manokwari District, Manokwari Regency, West Papua Province and compare it with the necessary water quality standards. In Indonesia, to guarantee the suitability of well water, water quality standards are stipulated in the Regulation of the Minister of Health Republic of Indonesia No. 32 of 2017. The research results show that the TDS, temperature, turbidity, sulfate, nitrate, iron, manganese and pH parameters meet the quality standards, while the chemical parameters nitrite, chromium (VI) and total coliform do not meet the quality standards. Therefore, it is necessary to treat the water to reduce levels of nitrite, chromium (VI) and total coliform before well water is consumed by residents.
Pengaruh Karbonisasi Terhadap Kualitas Karbon dan Nilai Kalor Pada Paduan Serutan Kayu Linggua dengan Tempurung Untuk Pembriketan Sebagai Bahan Bakar Alternatif Mangallo, David; Agusinus, Agusinus; Allo, Elisabeth Payung
Jurnal Natural Vol. 19 No. 2 (2023): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v19i2.263

Abstract

Karbonisasi biomassa atau yang lebih dikenal dengan pengarangan adalah suatu proses untuk menaikkan nilai kalor biomassa dan dihasi;kan pembakaran yang bersih dengan sedikit asap. Penelitian ini akan mengolah limbah serutan kayu dan tempurung menjadi bahan bakar briket dengan proses karbonisasi dengan menggunakan tabung kompressor bekas berkapasitas 25 liter. Alat yang digunakan untuk proses pengarangan adalah tabung reaktor yang dirancang dengan mempertimbangkan lubang aliran asap, lubang pengaturan aliran udara, dan saluran pembakaran. Proses pengarangan dilakukan dengan pengaturan pembukaan lubang oksigen mulai dari 30o sampai 180o. Pembuatan briket dilakukan dengan mencampur serbuk arang serutan kayu linggua sebanyak 60 %, serbuk arang tempurung sebanyak 30 %, dan perekat sebanyak 10 % lalu diaduk hingga merata. Proses pencetakan briket dilakukan dengan alat cetak briket yang dilengkapi dengan dongkrak hidrolik. Briket yang dihasilkan dari proses pencetakan kemudian dikeringkan dalam oven pengering dengan temperatur 60 oC selama 24 jam. Briket yang telah dikeringkan tersebut kemudian diuji dengan pengujian proksimate untuk mengetahui sifat-sifat fisis briket dan nilai kalornya. Dari hasil pengujian proksimate diperoleh bukaan katup terbaik adalah bukaan katup 150o karena memiliki kadar abu terendah (4,97%), kadar volatile matter terendah (35,80%), kadar fixed carbon tertinggi (52,27), dan nilai kalor tertinggi (5911 cal/gr)
PERBANDINGAN METODE DOUBLE EXPONENTIAL SMOOTHING BROWN DAN HOLT DALAM MERAMALKAN KEBUTUHAN ENERGI LISTRIK SEKTOR BISNIS (Studi Kasus: PT. PLN (PERSERO) ULP Manokwari Kota) Prita Larasati, Prita Larasati; Matulessy, Esther Ria; Nurhaida, Nurhaida
Jurnal Natural Vol. 20 No. 1 (2024): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v20i1.264

Abstract

Electric energy forecasting for the business sector is one of the solutions made to predict the need for electrical energy, especially the business sector, which is increasing every period. The purpose of this research is to forecast the electrical energy demand of the business sector to predict events that will occur in the future using mathematical models to minimize unwanted risks. Based on the data plot in the form of a linear trend and the research objectives, a comparison of the Brown and Holt double exponential smoothing methods is used in forecasting the electrical energy demand of the Manokwari City business sector to obtain the best model for the period August 2023 to July is 2024. The result of this study is to compare the best model obtained from the two models, namely Holt's double exponential smoothing with a forecasting model using parameters and with MAD value of , MSE value of , and MAPE value of .
The Monitoring by satelitte image to are and surface runoff in surrounding of governor office of west papua province: Monitoring by satelitte image to are and surface runoff in surrounding of governor office of west papua province Erari, Ishak Semuel; Edi Kuncoro, Edi Kuncoro; Kardiputra, Kwasti K.; Muslimin, Abdul Muis
Jurnal Natural Vol. 20 No. 1 (2024): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v20i1.266

Abstract

The development of Governor's Office of West Papua Province has cause change forest land area become using other land on the surrounding area, so that it has cause increasing the runoff surface wide and the coefficient of runoff . Objective of this study was for know development of the runoff surface wide and the average runoff coefficient with using satelitte image since 2010 to 2023. Results observation of satellite image that the runoff surface wide increase to 99.55 ha (56.25%) and average runoff coefficient increases from 0.32 to 0.56.
VARIASI RAGI PADA PEMBUATAN TEMPE KACANG MERAH (Phaseolus Vulgaris. L) Mogea , Rinondom AR; Siwi, Vanny H; Mogea, Rina A
Jurnal Natural Vol. 20 No. 2 (2024): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v12i2.278

Abstract

Red beans can be used as raw material for making tempeh because they contain many nutrients and are also known as a source of vegetable protein and this plant is widely grown in Indonesia. The aim of this research is to look at variations in different yeast dosages and look at fermentation times as well as organoleptic tests for each different yeast dosage in red bean tempe. The results of this study showed no significant difference in the aroma of raw red bean tempe using different amounts of yeast variations. On the other hand, there is a real influence on the color and texture of raw red bean tempe and the taste of fried tempe. This is proven by the asymptotic significance value which has a real influence and shows values ​​that are smaller than 0.05. For the yeast variation preferred by the panelists, the addition of 0.25 gr and for texture, aroma/smell and taste, the panelists chose the 0.50 gr sample because it still smelled of the typical tempe aroma with a savory, sweet and delicious taste. The time needed to make tempe is at time T5, which is 20-25 hours calculated from the time the yeast is added.
Pemanfaatan air hujan sebagai sumber air utama kampus Universitas Papua Manokwari Ruamba, Mariones; Erari, Ishak Semuel; Mirino, Rosalina; Muslimin, Abdul Muis
Jurnal Natural Vol. 20 No. 2 (2024): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v12i2.284

Abstract

The purpose of this study was to determine the amount of water storage obtained from rainwater collected through the roof of the building and the monthly water needs at the University of Papua (Unipa) Manokwari Campus. The results showed that the input of rainwater per year was 3.54 times more than the water usage on campus. All buildings on the Unipa Manokwari campus had a water surplus per month, except for the Faculty of Economics and Business building which had a water deficit from October to December. Buildings with a water surplus can act as buffers for buildings with a water deficit.
Ekstraksi Alumina dari Limbah Bungkusan Aluminium Sebagai Bahan Paduan Tanah Merah dalam Pembuatan Batu Bata Tahan Api (Fire-Resistant Brick) Sirampun, Alfhons Daniel; Stepanus, Jamius Bin
Jurnal Natural Vol. 21 No. 1 (2025): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v21i1.275

Abstract

Pada penelitian ini, telah dilakukan pengujian tahap awal sifat tahan api batu bata yang dibuat dari tanah merah dan alumina (Al2O3) sebagai bahan paduannya. Bahan Al2O3 diperoleh dari ekstraksi limbah bungkusan susu formula, sedangkan tanah merah yang digunakan berasal dari daerah distrik Warmare, Manokwari Barat, Papua Barat. Analisis kandungan tanah merah menggunakan XRF diperoleh komponen utama berturut-turut 39.57%, SiO2, 30,94% Al2O3 dan 23,73% Fe2O3. Proses ekstraksi dilakukan dengan metode gravimetri, melarutkan limbah alumunium dalam larutan HCl 18%, selanjutnya pengendapan Al(OH)3 menggunakan larutan Amoniak 25%. Konversi endapan Al(OH)3 menjadi Al2O3 dengan proses kalsinasi pada suhu 800 °C, hasil analisis XRF terhadap ekstrak yang diperoleh menunjukan 89.1% Al2O3, 3.95% SiO2, 3.06% NA2O dan 1.79% MgO. Batu bata dengan kandungan Al2O3 30% dan 50% menunjukan sifat tahan api setelah dibakar pada suhu 300 °C dan 500 °C karena batu bata tersebut tidak mengalami keretakan.
PREDIKSI CURAH HUJAN HARIAN KABUPATEN MANOKWARI BERBASIS LONG SHORT-TERM MEMORY Padang, Eohansen; Subgan, Aries A.; Kardiputra, Kwasti K.; Tukan, Tobias T
Jurnal Natural Vol. 21 No. 1 (2025): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v21i1.293

Abstract

An accurate daily rainfall prediction in tropical regions such as Manokwari Regency, West Papua Province, is critically important yet challenging due to high rainfall variability and complex climatic influences, including ENSO, IOD, and orographic effects. This study develops a Long Short-Term Memory (LSTM) model for daily rainfall prediction in Manokwari Regency, utilizing bias-corrected historical data from BMKG (2020-2024) and reanalysis ERA5 ECMWF Data (2005-2024) through Random Forest correction. Four LSTM architectures (Vanilla LSTM, Stacked LSTM, Hybrid CNN-LSTM, and Bidirectional LSTM (BiLSTM)) were evaluated with optimized hyperparameters (window size 30/60 days, batch size 32/64, learning rate 0.001), assessed using root mean squared error (RMSE) and mean absolute error (MAE) metrics. Results demonstrate that the BiLSTM model with two layers (64-32 nodes) and 60-day window size achieved superior performance (RMSE 10.55 mm/day, MAE 6.49 mm/day) compared to other architectures. While the LSTM model effectively captured seasonal rainfall patterns, deviations occurred during extreme events, potentially due to limitations in modeling long-term rainfall dynamics. These findings suggest LSTM's strong potential for early warning systems and water resource management in high-variability rainfall regions.
The Comparison of several earthquake decay models to predict the duration of aftershocks that occured in Manokwari Regency on April 21, 2012: Aftershock in Manokwari Regency on April 21, 2012 Auwliyah, Auwliyah; Ipa, Sangaji Hasmi Maharani; Pamuji, Kristian Enggar; Erari, Ishak Semuel; Muslimin, Abdul Muis
Jurnal Natural Vol. 21 No. 1 (2025): Jurnal Natural
Publisher : FMIPA Universitas Papua

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30862/jn.v21i1.296

Abstract

Has happen earthquake earth tectonics with magnitude 6.8 SR in Regency South Manokwari , West Papua Province on April 21, 2012. Purpose from study This is compare four decay models earthquake continuation namely the Omori , Mogi I, Mogi II and models Utsu to the earthquake data obtained from BMKG. Model with the smallest Root Means Square Error was the best earthquake decay model. Results matching curve shown the Mogi I and Utsu more suitable with earthquake decay data. Model of Mogi I and Utsu had mempredicted aftershocks for 15 days. Keyword: earthquake decay, aftershocks, Omori, Mogi I, Mogi II, Utsu

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